The same names are used for the different sizes:
- Finned X-Wing
- Size 2
- Finned Swordfish
- Size 3
- Finned Jellyfish
- Size 4
How it works
Here is an example of a Finned X-Wing:
The four cells marked X would be an X-Wing if the candidate in the cell marked F were not present. So either there is an X-Wing, or the candidate in F is true. In both cases, the starred cells cannot contain a candidate for this digit. We can eliminate those candidates.
The F cell is known as the fin. In this example, there could also be a candidate in r5c3. This would be called a big fin, but the effects are the same.